cannot hear other player speak in game mic

i don't know why can't i hear other people speak in dota2 using their mic.
i played a few games with my frens and i tried asking them to speak in mic,they spoke but i hear nth. other people can hear my fren speaking....
in dota2 i set the voice volume to max alrdy.
in set launch options,here are my setting:-novid -high -console -noforcemaccel -dxlevel 81

below is an picture of wad services i stopped when playing dota2.1233.png